COMBUSTION STUDIES OF FLUFF REFUSED-DERIVED FUEL (RDF) IN FLUIDIZED BED (FB) SYSTEM

Abstract

Among most conventional incineration systems, the
fluidized bed combustor (FBC) had been described as one of
the most advantageous by providing simple operation with
ability to accommodate low quality fuel as biomass, sludge
and MSW with high moisture; reduced auxiliary fuel use;
reduced operating and maintenance costs. This could only be
achieved if optimal operating parameters are determined.
This paper presents the methods and part of the findings of
an on-going research aimed at optimizing the operating
parameters that gives lowest emissions in the combustion of
a fluff refused-derived fuel (f-RDF) in pilot scale fluidized
bed combustor. The method adopt includes – cold
fluidization studies in rectangular model column to
determine the fluidizing velocity of the inert bed material
(silica sand), and the effects of increasing fluidizing numbers
on the mixing behavior of bed and fuel. This is closely
followed by combustion study in the pilot scale FBC.
Experimental findings from the cold fluidization studies
indicates that a sand with particle size range (300 – 600 μm)
gave a fluidizing velocity of 0.1 m/s at bed height 1W of
column. Similarly, fluidizing numbers of 4Umf and above
gave better mixing of inert bed material with fuel. Although,
the combustion study is at its preliminary stage, the results
from the cold fluidization shows that the fluidization is better
at bubbling fluidization regime against circulating
fluidization regime which requires much higher fluidizing
velocities and higher turbulence.